Field of the Invention
The present invention relates to a deposition apparatus for forming a protective film on a substrate.
Description of the Related Art
There is conventionally known a deposition apparatus for forming a protective film made of, for example, ta-C (Tetrahedral Amorphous Carbon) on a substrate. This deposition apparatus includes a filter unit in which the inner wall of a cylindrical electromagnetic coil serves as a vacuum partition, and assembled baffles are fixed on the inner wall of the electromagnetic coil (WO/1996/026531).
Since the filter unit of WO/1996/026531 is formed by assembling a plurality of flanges, the flanges need to be detached when exchanging or cleaning the baffles.
However, the operation of detaching flanges needs cost. In addition, if the positional relationship of electromagnetic coils changes when assembling the flanges, the path of an ion beam may also change, and reproducibility of deposition may be degraded. To prevent this, many man-hours are spent to position the electromagnetic coils.